土地利用方式对红壤氮转化过程的影响及其驱动因子研究

发布时间：2021-10-21 01:30

　　氮素是一种重要的生命元素,对于维持生态系统的组成、功能、健康等具有重要的作用。土壤氮素矿化作用、硝化作用和反硝化作用是关键的氮素循环过程,明确其速率及其影响因素对于认识土壤氮动态具有重要的意义。亚热带地区是中国重要的工农业生产基地,集中了全国22.5%的人口。为了满足人们对各种农业产品的需求,近70年来,该地区农业生产快速发展,土地利用方式发生了急剧的变化。该地区气候条件具有高温多雨的特点,淋溶非常强烈,土壤侵蚀严重,有机碳、氮含量普遍较低。土壤为酸性可变电荷土壤,脱硅富铁铝明显,土壤强酸性是限制农业生产的障碍因子之一。随着土地利用方式的变化,以及施化肥、有机肥、石灰等管理方式的改变,会显著影响土壤物理、化学、生物性质,进而可能影响土壤氮转化过程和土壤氮去向,引发与活性氮有关的环境问题。因此,阐明土地利用方式对红壤氮转化过程的影响,明确其主要驱动因子,对于制定针对性的管理措施,实现红壤氮素的合理调控具有重要的意义。江西省是中国典型的红壤分布区域,区域内林地、茶园、旱地、水田是主要的农、林业土地利用方式,其各占区域总面积的63.1%、0.3%、2.0%和10.5%。其中,毛竹是本区重要的... 

【文章来源】：南京师范大学江苏省 211工程院校

【文章页数】：182 页

【学位级别】：博士

【文章目录】：
Abstract
摘要
论文选题简介
研究目标、研究内容、研究方案和技术路线简介
论文核心研究结果简介
Chapter 1. Introduction
    1.1 Background
    1.2 Research Problem and Objectives
        1.2.1 Problem
        1.2.2 Objectives
        1.2.3 Novelty
Chapter 2. Literature Review
    2.1. Ecosystem
        2.1.1. Ecosystem Services
        2.1.2. Human Alteration ecosystem
        2.1.3. Land use, ecosystem, and ecosistem service
    2.2. Soils in the ecosystem
        2.2.1. The Role of Soils
        2.2.2. Soil Organic Matter (SOM)
        2.2.4. Antropoghenic Impacts,Litter Decomposition, and Soil OrganicMatter
    2.3. Nitrogen Cycle
        2.3.1 Nitrogen cycle in terrestrial ecosystem
        2.3.2. Mineralization and its affecting factors
        2.3.3. Nitrification and its affecting factors
        2.3.4. Denitrification and its affecting factors
        2.3.5. N_2O Emission from Nitirification and denitrification
    2.4. Subtropical region of China
    2.5. Site description and soil sample in this study
Chapter 3. Effects of land use on net rates of soil N mineralization andnitrification and nitrous oxide (N_2O) emission in subtropicalregion of China
    3.1. Introduction
    3.2. Materials and methods
        3.2.1. Site Description and soil sample
        3.2.2. Laboratory incubation for determining net N mineralization and netnitrification
        3.2.3. Determination of N_2O and CO_2 concentration
        3.2.4. Examine abundance of AOA and AOB
        3.2.5. Calculation
        3.2.6. Statistical Analysis
    3.3. Result
        3.3.1. Soil properties
        3.3.2. Ammonia oxidizer abundance (AOA and AOB)in the soil
        3.3.3. CO_2 and N_2O emission
        3.3.4. Net nitrification and N mineralization rates
    3.4. Discussion
Chapter 4. The denitrification potential and gas products in red soil underdifferent land use
    4.1.Introduction
    4.2. Materials and Methods
        4.2.1. Research area overview
        4.2.2. Anaerobic incubation experiment
        4.2.3. Sample analysis method
        4.2.4. Data processing and statistical methods
        4.2.5. Data analysis
    4.3. Results
        4.3.1 Soil properties
        4.3.2 nirS,nirK, and nosZ gene abundance
        4.3.3. N_2O and N_2 emission rate
        4.3.4. Denitrification potential
    4.4. Discussion
        4.4.1. Soil organic carbon is the main factor controlling the denitrificationpotential, N_2O and N_2 emission rate of red soil in different utilizationmodes
        4.4.2. Soil pH influences Different utilization methods N_2/N_2O ratio ofdenitrified gaseous products in red soil
    4.5. Conclusion
Chapter 5. The effect of soil pH on net rate of soil nitrogen mineralizationand nitrification in red soil and its mechanism
    5.1 Introduction
    5.2 Material and Method
        5.2.1 Soil Sampling and Preparation
        5.2.2 pH treatment and aerobic incubation experiment
        5.2.3 Calculation of Nitrogen Conversion Rate
        5.2.4 AOB and AOA Determination of abundance
        5.2.5 Data Calculation and Statistical Analysis
    5.3 Result
        5.3.1 Dynamics of Soil Inorganic Nitrogen Treated with Different pHValues
        5.3.2 Net Rate of Nitrogen Mineralization and Nitrification
        5.3.3 Variation of Abundance of AOB and AOA
    5.4 Discussion
        5.4.1 Effect of pH on Net Nitrogen Mineralization Rate
        5.4.2 Effects of pH and Mineralization on Net Nitrification Rate
Chapter 6. Effects of long-term manure and lime application on nitrogentransformation and fate in an upland soil in subtropical region
    6.1 Introduction
    6.2 Materials and methods
        6.2.1 Site description and long-term fertilization experiment design
        6.2.2 Soil column simulation test
        6.2.3 Laboratory ~(15)N tracing experiment
        6.2.4 ~(15)N tracing model
        6.2.5 Statistical analysis
    6.3 Result
        6.3.1 Physical and chemical properties of soil
        6.3.2 Gross N transformation rate
        6.3.5 N losses of each treatment in red soil
    6.4 Discussion
        6.4.1 Effects of long-term fertilizer management measures on Ntransformation in red soil
        6.4.2 The relationship between the characteristics of soil N transformationand N fate
    6.5 Conclusion
Chapter 7. General Conclusion
References
Appendix
Acknowledgement



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